Hitherto, a multiple air conditioner for a building to which an air-conditioning apparatus that performs a cooling operation or a heating operation by circulating a refrigerant between a heat source device (outdoor unit), which is a heat source machine arranged outside a room, and an indoor unit arranged inside the room so as to convey cooling energy or heating energy to a region to be air-conditioned such as an indoor space and the like is applied has existed (See Patent Literature 1, for example). As the refrigerant used in such an air-conditioning apparatus, HFC refrigerants, for example, are widely used. Also, a natural refrigerant such as carbon dioxide (CO2) and the like has begun to be used.
Also, an air-conditioning apparatus of another configuration represented by a chiller system is present. In this air-conditioning apparatus, cooling energy or heating energy is generated in a heat source machine arranged outside the room, the cooling energy or heating energy is transferred to a heat medium such as water, an anti-freezing solution and the like by a heat exchanger arranged in the heat source device, and the heat medium is conveyed to a fan coil unit, a panel heater and the like, which is an indoor unit arranged in a region to be air-conditioned so as to perform the cooling operation or heating operation (See Patent Literature 2, for example). Moreover, there is known a waste heat recovery type chiller in which four water pipelines are connected to a heat source machine so as to supply cooling energy or heating energy.
[Patent Literature 1] Japanese Unexamined Patent Application Publication No. 2-118372 (page 3, FIG. 1)
[Patent Literature 2] Japanese Unexamined Patent Application Publication No. 2003-343936 (page 5, FIG. 1)